The present application generally relates to a door closer, and more particularly, but not exclusively, relates to a door closer that harvests energy which is subsequently used to boost terminal shutting of the door.
Doors may not fully close for a number of reasons. Many hydraulic door closers are set to meet the Americans with Disabilities Act (“ADA”) requirement of 5 lbs. force to open the door. Due to this limited opening force, the amount of energy that can be stored in the hydraulic door closer is also limited. This may cause the door to have insufficient closing force to overcome adverse conditions such as pressure fluctuation due to operation of heating, ventilation, and air conditioning (“HVAC”) systems, friction forces, poor condition of door hardware, weather stripping, etc. In these situations, the user must either increase the closer spring force (which may in turn cause the door to not meet the ADA requirement), leave the door in a possible non-secure state, or invest in a powered door closing device such as an auto operator. Therefore, a need exists for further technological developments in the area of door closers.